The governing equation for the highly energetic IARWs in the unstable region (\(P/Q>0\) ) can be written as [1]}, [2]}
\(&&\hspace*{-28.45274pt}\Phi (\xi ,\tau )= \sqrt{\frac{2P}{Q}} \left[\frac{4(1+4iP\tau )}{1+16P^2\tau ^2+4\xi ^2}-1 \right]\mbox{exp}(2iP\tau ).\) 
